Flotation



-- I Patented Nov. 17, 1936 UNITED STATES FLOTATION Merrill W. MacAi'ee, Berkeley. Calif.

No Drawing. Application September 17, 1935, Serial No. 40,931

Claims.

This invention relates to the flotation of ores, more particularly to the use in froth flotation of gold, silver, copper, zinc, lead and similar ores of certain new reagents which increase the efli- 5 ciency of the flotation operation.

There have been used in the past a number of reagents which, added in small amounts to a pulp in a flotation circuit, aided in and caused the floating of the mineral particles in a froth which was then removed and the mineral recovered therefrom. Martin in 1914 at the Utah Copper Company showed the utility of xanthate in such a flotation operation; Christmann in Patent 1,837,852 of December 22, 1931 has disclosed the use of secondary butyl xanthate while Douglass in Patent 1,943,758 of January 16, 1934 has disclosed the utility of primary dixanthogens. Of the various reagents proposed, those most widely used are potassium ethyl xanthate, potas- 2 sium secondary butyl xanthate and potassium amyl xanthate. These reagents are in extensive use and are considered highly eflective in the flotation of ore and are taken as a standard of comparison for reagents.

2 I have discovered that a greater efliciency in flotation can be obtained from the use of dixanthogens, specifically the dixanthogens of secondary aliphatic monohydric saturated alcohols such as isopropyl alcohol, secondary butyl alcohol, diethyl carbinol, methylpropyl carbinol and methyl isopropyl carbinol and the secondary hexyl and heptyl alcohols. These new reagents have been extensively tested both in the laboratory and in large scale mill productions with uniformly superior results over those obtained with potassium secondary butyl xanthate which xanthate is usually more effective than potassium ethyl xanthate and the primary dixanthogens. In all cases the amount of mineral recovered from the pulp has been greater and the flotation operation has usually been facilitated by improvement in factors affecting flotation control. While it is true that in some cases the increased recovery has been small, in other cases it is quite large and 'in no case, regardless of the type ofcharacter of the ore floated, has the recovery been less than the recovery obtained by potassium secondary butyl xanthate. In some cases one of the secondary dixanthogens would be more effective than another while upon a different type of ore the eflectiveness wouldbe reversed. For example, upon an Idaho Maryland high .grade ore,

potassium secondary butyl xanthate showed a goldrecovery of 82%. Dixanthogen made from diethyl carbinol and secondary butyl xanthates thogen made from a Pentasol xanthate showed a recovery of 89%. On a Brunswick mill flotation head the secondary butyl xanthate showed a recovery of only while the dixanthogen from 5 potassium diethyl carbinol xanthate showed a. recovery of On a sample taken from the Mc- Donald tailing lease the secondary butyl xanthate showed a recovery of 76% while diethyl carbinol dixanthogen showed a recovery of 80%. 10

The flotation operations effected with the dixanthogen of the secondary xanthates were in all cases characterized by much easier flotation op; eration. The foregoing tests were all conducted under identical conditions except for the varia- 15 tion in flotation agents added. It is necessary to add a frothing agent in all cases inasmuch as the materials are not frothers. The amount of the flotation reagent necessary is relatively of the same order as that required for secondary 2o butyl xanthate and in comparative tests made with an increasing amount of both reagents, progressively increasing recoveries were secured but in every case the superiority of the reagents of this invention, dixanthogens of secondary alco- 25 hols, was apparent.

The reagents of this invention can be prepared in any desired manner and the invention, is not limited to the method of preparation of the materials.

In adding the dixanthogen Ihave successfully added it into the ore' being ground since it is stable enough to stand this. I have also incorporated the dixanthogen in the frother such as pine oil or Dupont frothing alcohols. The di- 35 xanthogen can be incorporated in an alcohol which is not a frother as secondary butyl alcohol although other alcohols and suitable solvents can be used.

My reagents have most probably the follow- 40 ing structural formula:

BOOB-SCOR' where R and R are the same or different alkyl 45 hydrocarbon radicals each having at least three carbon atoms and having the oxygen atom bonded to a carbon atom to which only one hydrogen atom is bonded. In other words, R and R represent the alkyl hydrocarbon radicals of the same 50 or diiferent secondary aliphatic monohydric saturated alcohols.

I claim:

1. In the process of concentrating ores and minerals by flotation, the step which comprises 55 subjecting the ore iii the farm of a huh to a froth flotation operation in the presence of seconmray hutyl dixanthogen.

2. In the process of concentrating ores and minerals by flotation, the step which one subjecting the ore in the form of a p to a froth flotation operation in the presence ct diethyi car: binol dixanthogen.

3. In the process of concentrating ores and minerals by flotation, the step which cemprises subjecting the ore in the form of a pulp to a froth flotation operation in the presence ct secondary amyl dixanthogens.

4. In the process of concentrating ores and! minerals by flotation, the step which comnriees aoenaor subjecting the ore in the form of a nulp to a froth flotation operation in the presence of a d thcgen of a seconr. monohydric aliphatic saturated alcohol.

5. In the process of concentrating ores and R W. MACE. 

